A wide variety of locking snap hook fasteners are available. Many of these fasteners, however, are overly-complicated, with many additional parts required and further requiring additional assembly, including the use of separate and additional locking pins or locking collars to prevent inadvertent or undesired opening of the snap hook fastener.
For example, U.S. Pat. No. 8,365,365 provides for a collar piece, referred to as a “keeper”, to prevent movement of a cylindrical closing member. A rotation of the collar piece is required to align a slot with the grip of the closing member, to allow the retraction of the closing member and opening of the snap lock.
Similarly, U.S. Pat. No. 7,472,461 provides for a complicated mechanism with many additional parts, such as a moveable sleeve and a pin mounted in a transverse bore with a second, additional bias spring, which is then seated in a recess when the closure shaft is closed, locking the closure shaft into the closed position, with additional button-type components required to release the locking pin.
Accordingly, a need remains for a fastener which may be readily implemented, without requiring additional parts or complicated manufacturing. Such a fastener should nonetheless require multiple, distinct and different movements to open the fastener, to avoid inadvertent or easy opening of the fastener, and thereby provide additional locking security.